This paper first evaluates the relative importance of the soil–plant–animal and soil–animal pathways of Zn, Cu and (especially) Pb investigated over a 15-month study period at 12 floodplain sites ...located within and downstream of the mineralised and historic mining area of mid-Wales, and secondly considers the implications of a sequential extraction procedure (SEP) undertaken on soils of varying particle size sampled from the study locations. Generally, very good agreement was found between the chemical partitioning of the three metals for each of the physical soil fractions subjected to the SEP. The availability of Pb to pasture vegetation, especially at the contaminated sites, is indicated with its associations with the more soluble (i.e. exchangeable and Fe/Mn oxide) soil phases, yet soil and/or plant barriers effectively restrict above-ground herbage concentrations of this metal. Consequently, with sheep ingesting soil at rates varying according to season from 0.1% to 44% or more of dry matter intake, the soil–animal pathway accounts for the majority of Pb consumption through most of the year, and at moderately and highly contaminated sites significant quantities of relatively soluble soil–Pb can be ingested at rates exceeding safety threshold limits.
Gill disorders have become a significant problem during the marine phase of farming Atlantic salmon (Salmo salar L.). The term complex gill disease (CGD) includes a wide range of clinical gill ...disease presentations generally occurring from the end of summer to early winter on marine Atlantic salmon farms. The gross and histological lesions observed are the resultant culmination of exposure to a mixture of environmental insults, pathogenic organisms and farm management practices. None of the three principal agents purportedly associated with CGD (Desmozoon lepeophtherii, salmon gill poxvirus or Candidatus Branchiomonas cysticola) have been cultured successfully in-vitro, so individual in-vivo challenge studies to identify their pathogenesis have not been possible. Studies of cohabitation of single pathogen-infected fish with naïve fish, and epidemiological investigations are required urgently to elucidate the roles of these pathogens and other factors in CGD.
This ultrasonographic study monitored lesions involving the lung surface suspected to be the early stages of ovine pulmonary adenocarcinoma (OPA) tumours over 4 months in commercially farmed sheep. ...The enlargement of these lesions defined ultrasonographically, which likely represent the development of OPA tumours, have important implications for ultrasound screening schedules in veterinary management plans attempting to eliminate OPA by test-and-cull.
The lungs of 58 adult Scottish Blackface sheep with ultrasonographic changes at the lung surface consistent with early OPA tumours were examined two to six times over 40 to 290 days. Lesion development, represented in early video recordings by 2-3 mm lesions involving the visceral pleural and comet tails, then a decreasing length of the hyperechoic line representing the normal visceral pleura and increasing depth of the sharply-demarcated and largely uniform hypoechoic areas into the lung parenchyma, was found in 26 of the 58 sheep. The rate at which the sonographic lesions progressed varied considerably and in 10 of 17 Group 1 sheep developed quickly from an estimated depth of 2-30 mm up to 70 mm between 60 and 120 days later. These sonographic lesions were confirmed as OPA at necropsy; histological changes of concurrent bacterial infection were detected in one of these 10 Group 1 sheep. Thirty-one sheep had sonographic changes ≤30 mm consistent with very early OPA at the first examination which had reduced or were not observed at subsequent examination. Five of these 31 sheep were necropsied, 3 had small OPA lesions while 2 had no significant pathology.
Lesions involving the visceral pleura, with sonographic changes consistent with previous published findings of early OPA, developed over 40-120 days to large masses in 10 of 17 Group 1 sheep with the provisional sonographic diagnosis confirmed histologically at necropsy. While it is possible that atalectic lung could have caused some of the minor sonographic changes there was no microscopic evidence of pathologies other than OPA in nine of 10 Group 1 sheep. We conclude that some small tumours progress to large tumours within 3 months questioning the assumption that OPA is a slow growing tumour in adult sheep taking several years to cause clinical disease. The findings that a proportion of small ultrasonographic lesions are not found again at subsequent scanning illustrates the challenges of interpreting small (< 1-2 cm) lesions during rapid whole flock ultrasonographic examination and we continue to recommend re-scanning suspicious sonographic changes 2 months later.
Sheep grazing metal-contaminated floodplain pastures across mid-Wales ingest high concentrations of lead (Pb) in vegetation and directly in the form of soil. Sheep whole blood analysis indicated that ...Pb concentrations can be significantly elevated for animals grazing contaminated sites: in winter/spring, a median blood concentration of 147
µg
Pb
l
−
1
was found at the location with the highest soil enrichment of this metal compared to only 26
µg
Pb
l
−
1
for the control flock. There was within-flock variability in blood–Pb concentration, and overlap between blood–Pb ranges in animals grazing control and contaminated sites, although use of the Kruskal–Wallis
H test established a number of significant (
P
<
0.05) differences between the blood–Pb content of flocks grazing the various study locations. Despite total daily intakes of up to 723
mg
Pb
d
−
1
, only one individual sheep showed a blood–Pb content above the ‘normal safe’ concentration of 250
µg
l
−
1
. Blood and wool analyses were found to have limited value for the diagnosis of environmental exposure to Pb, and further consideration of metal accumulation in offal, bone and muscle tissue is recommended.
Louping-ill (LI), caused by louping-ill virus (LIV), results in a frequently fatal encephalitis primarily affecting sheep and red grouse (Lagopus lagopus scotica), but it does occur in other species. ...An adult male Border collie dog was definitively diagnosed with fatal LI and the lesion profile, LIV antigen distribution and full genome sequence of the LIV responsible were investigated to determine if this differed significantly from sheep-derived LIV. No gross lesions were present. The histological lesions were confined to the central nervous system and comprised of lymphocytic perivascular cuffs, glial foci, neuronal necrosis and neuronophagia. Immunolocalization of viral antigen showed small amounts present in neurons only. These histological and immunohistochemical findings were similar to those reported in affected sheep. Compared with published full genome sequences of sheep-derived LIV, only very minor differences were present and phylogenetically the virus clustered individually between a subclade containing Scottish strains, LIV 369/T2 and G and another subclade containing an English isolate LIV A. The LIV isolated from the dog shares a common progenitor with LIV A. These findings suggest there is no canine-specific LIV strain, dogs are susceptible to sheep-associated strains of LI and with the increase in tick prevalence, and therefore exposure to LIV, a safe, effective vaccine for dogs may be required.
European moles (Talpa europaea) are a common species in the UK, but there are few published data on the causes of mortality in these animals. An opportunistic post-mortem study was carried out on ...44 moles found dead or dying in Cornwall, UK. Assessment of muscle condition and fat reserves, where possible, indicated that most (27 of 37, 73%) were in good nutritive condition. The majority had died of trauma (n = 40, 91%), the principal cause of which was predation (n = 36, 81.8%) by foxes and domestic cats and dogs. The carcases were in a variable state of preservation, but 28 cases were suitable for histopathological examination. This revealed lesions in the lungs of 92.8 % (26 of 28) of the animals. The commonest lesions comprised localized infiltration of the parenchyma by macrophages and eosinophils and in most cases the lesions were unlikely to have been of clinical significance; in two cases they were associated with infection by a parasitic nematode. One mole showed severe pneumonitis and hepatitis caused by infection with Toxoplasma gondii. Adiaspiromycosis was diagnosed in two moles, one by direct microscopical examination of the lung and one by histopathology; the lesions were not considered to be of clinical significance. Severe pleurisy and pericarditis caused by infection with Streptobacillus moniliformis was seen in a mole that had suffered bite wounds to a foot previously. Cholangitis due to infection by a protozoal parasite, provisionally identified as Cyclospora talpae, was a common histopathological finding (11 of 28, 39.3%); infection by the parasite did not appear to affect body condition adversely. Miscellaneous conditions identified were ulcerative dermatitis associated with gram-positive cocci (n = 1), extra medullary haemopoiesis in spleens (six of 12, 50%) and mineralized foci in pulmonary blood vessels (three of 28, 10.7%). No significant pathology was seen in the kidneys. This study suggests that the health status of moles in Cornwall is generally good and predation is a common cause of mortality. Pulmonary disease, associated in some cases with nematode infections, is also prevalent, but probably of little clinical significance. There is a high prevalence of cholangitis due to infection with a protozoan parasite believed to be C. talpae. Other diseases identified include adiaspiromycosis, streptobacillosis and toxoplasmosis.
Summary
Background
Neutrophil apoptosis and phagocytic clearance have been proposed as key determinants affecting the resolution of airway inflammation.
Objective
To determine the kinetics of ...neutrophil priming, recruitment, activation and subsequent clearance in a naturally occurring equine disease model of neutrophilic pulmonary inflammation.
Methods and Results
A 5 h mouldy hay/straw challenge in hypersensitive horses induced transient pulmonary dysfunction lasting 4 days. At 24 h circulating neutrophils were primed and displayed delayed rates of spontaneous apoptosis in vitro. Neutrophil numbers in the airspaces peaked at 5 h and then fell abruptly, returning to pre‐challenge levels by 4 days. Airspace neutrophils demonstrated increased respiratory burst activity compared with circulating cells and equine neutrophil elastase 2A concentrations increased in parallel with neutrophil numbers indicating in vivo priming and degranulation. The number of apoptotic neutrophils and proportion of alveolar macrophages containing phagocytosed apoptotic neutrophils increased significantly at 24 h and 4 days post‐challenge corresponding to the period of most rapid neutrophil clearance.
Conclusion
This is the first demonstration of spontaneous neutrophil apoptosis and phagocytic removal in a natural disease model of airway inflammation and provides critical kinetic data to support the hypothesis that this clearance pathway plays a central role in the resolution of neutrophilic inflammation.
Cardiovascular disease is the leading cause of human mortality and disability worldwide, primarily due to myocardial infarction (MI) and the resultant heart failure. To address this, animal models of ...MI have been developed to better understand the pathophysiological process and to enable the discovery and development of new therapies. The most commonly used small and large mammal models of MI accurately reproduce histopathologically the four characteristic post–MI phases: cardiac cell death, inflammation, myocardial repair and remodelling. However, differences between the time of onset of each characteristic phase and the kinetics of various cellular reactions between human MI and animal models, and between animal models, require careful consideration when defining the variables to be analysed and the timepoints of assessment in experimental studies. Typically, the progression of the different phases post–MI occur more rapidly in rodent models compared with large-animal models and man, suggesting the use of large-animal models is more translational for studying human MI. This review provides an overview of the main anatomopathological features of small and large animal models of MI and discusses the key species-specific histopathological similarities and differences.
The Gough bunting (Rowettia goughensis) is indigenous to Gough Island and critically endangered due to predation by invasive house mice (Mus musculus). A planned ecosystem restoration by eradication ...of house mice via aerially delivered rodenticide requires a reproductively balanced population of Gough buntings being held in captivity to avoid primary and secondary poisoning. To aid disease detection during the period of captivity, Gough buntings (n = 25; five adult females, 15 adult males and five juveniles) were captured, measured and sampled to determine reference ranges for routine haematological and biochemical parameters and to identify any faecal bacterial species and intestinal and haemoparasites. Adult females had significantly higher blood glucose (P = 0.02 and 0.05 for different analyzers) and globulins (P = 0.02) than adult males or juveniles, and juveniles had consistently higher, although not significant, concentrations of creatine kinase. Juveniles had significantly (P = 0.007) more heterophils than adults; eosinophils were rare in adults and absent in juveniles and azurophils were absent from all individuals sampled. No parasite eggs were found in the faeces and no haemoparasites were found in blood smears. Several faecal bacterial species were recorded including Enterococcus spp. (n = 12), Klebsiella spp. (n = 7), Staphylococcus aureus (n = 6), Staphylococcus intermedius (n = 1), Escherichia coli (n = 1) and Pseudomonas spp. (n = 1). No overt clinical or subclinical disease was found in any of the birds examined, which suggests they are suitable for short-term captivity during ecosystem restoration and the data will provide key haematological and biochemical reference ranges for monitoring their health. However, the capture of a reproductively balanced population may require significant effort due to the relative difficulty with which females were caught.
Fatal marine
Brucella
infections with histologic lesions specific to the central nervous system (CNS), known as neurobrucellosis, have been described in 5 species of odontocete cetaceans in the UK: ...striped dolphins
Stenella coeruleoalba
, Atlantic white-sided dolphins
Lagenorhynchus acutus
, short-beaked common dolphins
Delphinus delphis
, long-finned pilot whale
Globicephala melas
and Sowerby’s beaked whale
Mesoplodon bidens
. To date, these CNS lesions have only been associated with
Brucella ceti
ST26 and not with
B. pinnipedialis
, which is rarely isolated from cetaceans and, although commonly found in various seal species, has never been associated with any pathology. This paper describes the first report of neurobrucellosis in a common minke whale
Balaenoptera acutorostrata
which was associated with the isolation of
Brucella pinnipedialis
ST24 and co-infection with
Balaenoptera acutorostrata
gamma-herpesvirus 2. This is the first report of neurobrucellosis in any species of mysticete and the first report of
Brucella pinnipedialis
in association with any pathology in any species of marine mammal, which may be due to co-infection with a herpesvirus, as these are known to be associated with immunosuppression.
PDF
